The estranged wife of a recently jailed businessman has told the high court in London she would settle for £300m plus legal expenses from her husband.

In the latest round of the epic divorce battle between Michelle and Scot Young, the judge, Mr Justice Moor, is making a fresh attempt to discover how much the property dealer is worth.

Michelle Young, 49, claims her former partner owns assets worth "a few billion at least". Scot Young, 51, has told judges he is penniless and bankrupt, a victim of financial meltdown and hopelessly insolvent.

In January, Moor imposed a six-month prison term on Scot Young after concluding that he had failed to provide financial information to his wife and was in contempt of court.

The couple, who live in London and have two daughters, separated in 2006 after starting a relationship in 1989. They have been feuding over money for several years.

The trial is taking place in the family division of the high court, where Moor has given permission for it to be reported.

When Michelle Young was asked by a lawyer how much she would settle for, she replied: "£300m plus all my legal expenses". She said in 2006 that a schedule of assets contained a figure of £400m.

Of her former luxury lifestyle, she said: "We had vast estates. We had staff." She told the court she went on three or four foreign holidays a year, staying in villas and presidential suites, and that she and husband ate at a Raymond Blanc restaurant twice a week.

"We had a chandelier in our drawing room. The other chandelier sits in the White House," she said. "They were valuable assets."

Michelle Young said they had moved house a number of times, making a £10m profit on one home, and that her husband had paid between £2m and £4m for a yacht, "a flash gin palace, Sunseeker-type boat" and had talked about buying a "very expensive helicopter" to fly between one of their homes near Oxford and London.

She said Scot Young dealt in property, and had told her father that he had made "vast money" but that he had otherwise been very secretive about his finances.

She said they had lived in Belgravia, central London, for three or four years and in Miami, where they owned three Porsche cars.

"There was a vast fortune hidden," she said. "This has dragged through the courts for seven years, mostly because of my husband's lack of disclosure and playing the system. He used offshore vehicles and many advisers and accountants to layer these assets."

She said she wanted a £25m home in Belgravia. "It's a nice area. It's very safe," she said. "This case is not about means. It's about quality."

She said the case was like no other in the family division of the high court.

"Vast amounts of assets have been concealed," she said. "It was a very long marriage. My children and I should be entitled to a fair share of those assets."

She was questioned by Scot Young, who is representing himself. And at one point during questioning, he asked the judge: "Is this kind of ranting allowed?"

Rex Howling QC, for Michelle Young, told the judge in written submissions: "Mrs Young is adamant that Mr Young has access to large sums of money and that these funds are secreted in cleverly constructed offshore tax vehicles."

Moor told the court: "I have to decide on the balance of probabilities how much Mr Young is worth."